Electrical heating appliance



April 26, 1966 J. w. BouGHToN 3,248,519

ELECTRICAL HEAT APPLIANCE Filed Aug. 8, 1963 F55. ll

INVENTOR.

111i 111 Jamwf/@gzegfzzafz United States Patent() t 3,248,519 ELECTRICAL HEATING APPLIANCE James Wallace Boughton, Georgetown, Ky., assignor to Electric Parts Corporation, Georgetown, Ky., a corporation of Illinois Filed Aug. 8, 1963, Ser. No. 300,889 4 Claims. (Cl. 219-528) This invention relates generally to electrical heating appliances, and more specifically to an improved electrically heated bed covering.

Although the principles of the present invention may be included in various bed coverings, such as electric blankets and electric sheets, a particularly useful application is made in an electrically heated mattress pad. vEach of these named types of bed covering includes a relatively large rectangle of one or more layers of textile, and may include one or more layers of non-woven textile therewith. Such material, when subjected to laundering, usually shrinks. This is Ipartciularly true the first time that the same is laundered. When the device includes elec-tric heating wire attached thereto, such shrinkage of the textile portion during laundering causes a shortening of the wiring pattern, but not of the wire itself. The heating wire compensates for the `textile shrinkage by axial movement into terminal pockets or any other regionin the wiring diagram where clearance has been provided. This creates an undesirable accumulation of twiring and of heat in these regions when the pad is subsequently used. The problem is particularly accentuated when two hea-ting wires are employed together in side-by-side relation since a rather snug attachment is inherently created in commercial articles owing to the fact that commercially available sewing equipment of the two-needle type will produce such tit.

The present invention contemplates the utilization of a textile tape which'overlies the heating wire, which extends continuously therewith, and which therefore is arranged or disposed in `an identical pattern which is always serpentine in f-orm in -that it includes curved portions. The most important feature of this tape is that it is provided with a normally collapsed pleat lying outside of the zone in-itially occupied by the heating wire, such pleat being openable or expandable by the he-ating wire in response to shrinkage of the ltextile bed covering Y and/ or textile tape.

Accordingly, it is an object of the present invention to provide an improved electrically heated bed covering.

Another object .of the invention is to provide structure by which the heating wire pattern of an electrical bed covering will be preserved without bunching any heating wire, even though there is a shrinkage of the textile portion.

A still further object of the present invention is to provide a textile bed covering which is so constructed as to be able to hold a heating wire in a predetermined pattern, both before and after any shrinkage thereof.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and to the accompanying sheet of drawings in which a preferred structural embodiment incorporating the principles of the present invention -is shown by way of illustrative example.

On the dra-wing:

FIGURE 1 is a diagram of an electrically heated bed covering illustrating a heating wire pattern;

4FIGURE 2 is a fragmentary elevational view of an electrically heated bed covering illustrating in elevation one of the pattern bends indicated diagrammatically in FIG- URE 1;

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FIGURE 3 is an enlarged cross-sectional view take along line III-III of FIGURE 2; and

FIGURE 4 is an enlarged cross-sectional view taken along line IV--IV of FIGURE 2,l but representing such view taken after shrinkage ofthe textile portion of the bed covering.

As shown in the drawings:

The principles of this invention are particularly useful when embodied in an electrical bed covering assembly such as diagrammatically illustrated in FIGURE l, generally indicated by the numeral 10. The device includes a textile bed covering 1'1, such as a mattress pad, blanket, or sheet, each sized substantially as large as the bed mattress with which the same is tobe employed. To this bed covering 11, there is secured a heater wire arranged in a pattern, the pattern being represented by the numerals 12 and 13. The heater wire begins at a plug 14 and follows one of the patterns 12, 13 to an innermost dead end, and there reverses and follows the same pattern back -to the plug 14 so that at any point in the pattern, there are two separate wires.

A typical mattress pad size is 54 inches by 76 inches, and it is evident that a piece of textile of this size, if subjected to shrinkage, would have a very appreciable amount of shrinkage. A typical heating wire employed to provide the double wires of the patterns 12 and '13 would be 188 feet long, and have an electr-ical resistance of about 3 ohms per foot, To hold such a quantity of wire in a predetermined pattern, there is employed a tape 1S, preferably of a -textile with a shrinkage factor of about the same as the bed covering 11. In the fabrication of this device, a two-needle sewing machine is employed to provide two seams 16, 17 simultaneously along lines parallel to the tape and to the wire enclosed therein. The heating wire is shown in FIGURE 3 and is indicated by the numeral 18.

The main feature of this invention is that the tape 15 is provided with a pleat generally indicated at 19 which has a closed edge 20 and an open end 21 directed toward the heating wire 18, the pleat 19 being normally collapsed and overlying the line of stitches 17.

During manufacture, the tape 15 is provided so that the pleat 19 is present therein prior to the stitching. rThe feet of the sewing machine, during stitching, pass closely along the heating wire 18, 18, one of them being under the pleat 19. Upon completion of the sewing operation, the pleat y19 of itself reassumes a nearly at and collapsed position, such as shown in FIGURE 3. Substantially this cross-section is present at any point transverse to a leg of either pattern 12 or 13, initially.

However, if shrinkage should occur, the pleat 19 provides room or clearance for receiving the non-shrinking heating wire. Referring to FIGURE 1, assume that there has been longitudinal shrinkage. The Wire situated in the pattern leg 22 will tend to move axially since it is retained laterally by the snug tit provided by the tape 15. Such axial movement in effect produces a lateral shift of `the heating wire 18 at the end 23 so as to cause the heating wire 18 to expand or .open the pleat 19 as shown in FIG- URE 4 when the shrinkage of the bed covering 1f1 is taking place.

Initially, the heating wire 18 and the tape 15 are applied simultaneously so that there `is no tendency for the heating wire '18 to open any pleat 19 prematurely. The tendency of the pleat 19 to remain collapsed causes a crease indicated at 24 to hold the tape 15 in snug position against t-he heating wire 18 to maintain the heating wire arrangelment pattern initially. However, this crease readily yields in response to the higher forces present during shrinkage of the bed covering 11.

The embodiment shown in FIGURES 2-4 represents a mattress pad wherein the 4bed covering 11 includes a woven sheet 25, a woven sheet 26, and non-wovenv textile lfibers 27 disposed therebetween. The elements 25-27 are stitched together elsewhere in a conventional manner to form the mattress pad type of bed covering. Such additional stitching is not shown and is conventional, and is accomplished prior to the attachment of the tape thereto by the lines of stitches 16, 17. The edges of the tape 15 are turned in and also held by the lines of stitches 16 and 17.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

\1. An electric heating appliance comprising in combination:

(a) a textile bed covering;

(b) heater wire disposed at an outer surface thereof in a serpentine arrangement;

(c) a tape extending continuously along the length of and enclosing said heater Wire;

(d) stitch means closely adjacent to a side of said heater wire, and securing said heater wire within said tape and securing said tape to said bed covering against said outer surface; and

(e) said tape having a normally collapsed expandable pleat extending along its length at said line of stitches, said pleat opening toward said heater wire and overlying said line of stitches.

2. An electric heating appliance comprising in combination:

(a) a textile bed covering;

(b) heater iwire disposed at an outer surface thereof in a serpentine arrangement;

(c) a tape extending continuously along the length of Iand enclosing said heater wire;

(d) a pair of lines of stitches respectively closely adjacent to opposite sides of said heater wire and sel pleat extending along its length between said lines of stitches.

3. An elect-ric heating appliance comprising in cornbination:

( a) a textile bed covering;

(b) heater wire disposed at an outer surface thereof in a serpentine arrangement;

(c) a tape extending continuously along the length of and enclosing said heater Wire;

(d) a pair of lines of stitches respectively closely ad jacent to opposite sides of said heater wire and securing said tape to said bed covering against said outer surface; and

(e) said tape having a normally collapsed expandable pleat extending along its length `between said lines of stitches, said pleat opening toward said heater wire and overlying one of said lines of stitches.

4. An electrc heating appliance comprising in combination:

(a) a textile .bed covering;

(b) heater wire disposed at an outer surface thereo in a serpentine arrangement;

(c) a tape extending continuously along the length of and enclosing said heater wire;

(d) a pair of lines of stitches respectively closely adjacent to opposite sides of said heater wire and securing said tape to said bed covering against said outer surface; and

(e) said tape having a normally collapsed expandable pleat extending along its length between said lines of stitches, the closed edge of said pleat being directed away from said heater Wire.

References Cited by the Examiner UNITED STATES PATENTS 2,569,138 9/1951 -Abbott 219--212 l2,636,174 4/ 1953 Williams 2--260 X 2,712,592 7/-1955 Goldstein et al 219-217 3,072,776 1/ 1963 Quenneville 219-212 FOREIGN -PATENTS 760,447 12/ 1933 France. 767,954 2/ 1957 Great Britain.

RICHARD M. WOOD, Primary Examiner.

V. Y. MAYEWSKY, Assistant Examiner. 

1. AN ELECTRIC HEATING APPLIANCE COMPRISING IN COMBINATION: (A) A TEXTILE BED COVERING; (B) HEATER WIRE DISPOSED AT AN OUTER SURFACE THEREOF IN A SEPARATING ARRANGEMENT; (C) A TAPE EXTENDING CONTINUOUSLY ALONG THE LENGTH OF AND ENCLOSING SAID HEATER WIRE; (D) STITCH MEANS CLOSELY ADJACENT TO A SIDE OF SAID HEATER WIRE, AND SECURING SAID HEATER WIRE WITHIN SAID TAPE AND SECURING SAID TAPE TO SAID BED COVERING AGAINST SAID OUTER SURFACE; AND (E) SAID TAPE HAVING A NORMALLY COLLAPSED EXPANDABLE PLEAT EXTENDING ALONG ITS LENGTH AT SAID LINE OF STITCHES, SAID PLEAT OPENING TOWARD SAID HEATER WIRE AND OVERLYING SAID LINE OF STITCHES. 